With the widespread use of cellular phones, various types of cellular phones have been emerged in the market for satisfying various user demands. The physical designs of cellular phones have been evolved from a bar type to folder and slide types via intermediate flip and flip-up types. A typical slide type cellular phone is characterized in that a sliding body is slidably moved to a predetermined position in the lengthwise direction on a main body so that a user can push and pull the sliding body to open and close the cellular phone, which enables the user to use the slide type cellular phone in a simpler manner. This operational mechanism can ensure slimness and compactness of sliding type cellular phones while maintaining a large display screen size similar to folder type cellular phones. Based on these advantages, sliding type cellular phones are currently recognized as high-grade phones. Recently, sliding type cellular phones have employed an automatic sliding mechanism wherein a sliding body is completely slid up by pushing it to a predetermined position. Under such circumstances, various sliding units have been developed to realize the automatic sliding mechanism.
A sliding type cellular phone is disclosed in Korean Registered Utility Model No. 387257, which was filed by the present applicant. The sliding type cellular phone will be briefly explained below.
As shown in FIGS. 1 and 2, a sliding unit 30 is disposed between a first body 10 and a second body 20 whose faces are at an obtuse angle. The first and second bodies 10 and 20 are curved to have a predetermined curvature, so that the first body 10 can be moved relative to the movement of the second body 20 in a circular arc direction. The sliding unit 30 includes a first sliding member 31 mounted on the facing surface of the first body 10 and a second sliding member 32 mounted on the facing surface of the second body 20. The first body 10 is sliding up and down relative to the second body 20 by means of the sliding unit 30. The first and second sliding members 31 and 32 are arranged at an obtuse angle and are united together by guide rails. The guide rails have the same curvature as the first and second sliding members 31 and 32, and as a result, the first body 10 is slid up and down along the second body 20. The sliding unit 30 is provided with a pin spring 40 to allow the first and second sliding members 31 and 32 to be supported to each other by an elastic force and slidable with respect to each other. A space is provided between the facing surfaces of the first and second bodies 10 and 20 to prevent the pin spring 40 from interfering with the facing surfaces of the first and second bodies 10 and 20 upon the sliding movement of the first and second bodies 10 and 20 in a circular arc direction.
However, the space defined by the facing surfaces of the first and second bodies 10 and 20 makes it difficult to secure spaces for other elements, causing many limitations in the compactness and slimness of cellular phones in size.
In the meantime, the first and second sliding members and guide rail are formed of a metallic material by press molding so as to have the same curvature. However, the press molding is a very complicated process to perform and causes various unexpected problems such as wear of a press arising from repeated operations, variation in the thickness of metallic materials and proficiency of operators.